8 research outputs found

    The Ultrafine-Grain Yttria-Stabilized Zirconia Reinforced β-Titanium Matrix Composites

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    Ti(β) alloys have become an important class in the biomedical field due to low Young’s modulus, excellent physical properties, and biocompatibility. However, their properties, like biocompatibility and, also, low wear resistance, can be still enhanced. To improve those properties, a composites approach can be applied. This research shows a new approach of the composite structure fabrication by powder metallurgy methods which for a stabile yttria-stabilized zirconia (YSZ) reinforcement phase could be obtained in the ultra-fine grain range beta-titanium matrix. In this work, the composites based on ultrafine-grain Ti-xMo (x = 23 wt%, 27 wt%, 35 wt%) alloys with addition 3 wt%, 5 wt% or 10 wt% YSZ, and 1 wt% Y2O3 were fabricated by the mechanical alloying and hot-pressing approach. Obtained composites were characterized in terms of their phase composition, microstructure, Young’s modulus, hardness, surface free energy (SFE), and corrosion resistance. The structure of composites consists of phases based on Ti–Mo, Ti(α), and YSZ. The oxide (YSZ) powder tends to agglomerate during processing, which is revealed in composites based on Ti23Mo and Ti27Mo. However, composites based on Ti35Mo are characterized by a high degree of dispersibility and this influences significantly the hardness value of the composites obtained. Only in the case of composites based on Ti35Mo, the decrease in Young’ Modulus is observed. All composites possess a hydrophilic surface property and good corrosion resistance

    Nursing care of a patient diagnosed with malignant breast cancer during chemotherapy using ICNP® terminology

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    Introduction. Oncology nursing as a specialized field ought to develop a range of standards that will increase the quality of patient care. The indispensable ability of a nurse is to create patient-specific diagnoses that holistically describe the biopsychosocial status of the care focus

    Possible influence of social media on shaping the image of nurses on the Internet

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    Introduction. Nowadays, a professional image is an important element of the identity of individual professions. Its formation is a difficult process, dependent on many factors, including the use of new communication channels, such as social media, which in recent years have become a space for expressing social opinion, including those concerning individual professions

    Laser Surface Alloying of Austenitic 316L Steel with Boron and Some Metallic Elements: Microstructure

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    Austenitic 316L steel is known for its good oxidation resistance and corrosion behavior. However, the poor wear protection is its substantial disadvantage. In this study, laser surface alloying with boron and some metallic elements was used in order to form the surface layers of improved wear behavior. The microstructure was studied using OM, SEM, XRD, and EDS techniques. The laser-alloyed layers consisted of the only re-melted zone (MZ). The hard ceramic phases (Fe2B, Cr2B, Ni2B, or Ni3B borides) occurred in a soft austenitic matrix. The relatively high overlapping (86%) resulted in a uniform thickness and homogeneous microstructure of the layers. All the laser-alloyed layers were free from defects, such as microcracks or gas pores, due to the use of relatively high dilution ratios (above 0.37). The heat-affected zone (HAZ) wasn’t visible in the microstructure because of the extended stability of austenite up to room temperature and no possibility to change this structure during fast cooling. The use of the mixtures of boron and selected metallic elements as the alloying materials caused the diminished laser beam power in order to obtain the layers of acceptable quality. The thickness of laser-alloyed layers (308–432 μm) was significantly higher than that produced using diffusion boriding techniques

    In Vitro and In Silico of Cholinesterases Inhibition and In Vitro and In Vivo Anti-Melanoma Activity Investigations of Extracts Obtained from Selected <i>Berberis</i> Species

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    Berberis species have a long history of use in traditional Chinese medicine, Ayurvedic medicine, and Western herbal medicine. The aim of this study was the quantification of the main isoquinoline alkaloids in extracts obtained from various Berberis species by HPLC, in vitro and in silico determination of anti-cholinesterase activity, and in vitro and in vivo investigations of the cytotoxic activity of the investigated plant extracts and alkaloid standards. In particular, Berberis species whose activity had not been previously investigated were selected for the study. In the most investigated Berberis extracts, a high content of berberine and palmatine was determined. Alkaloid standards and most of the investigated plant extracts exhibit significant anti-cholinesterase activity. Molecular docking results confirmed that both alkaloids are more favourable for forming complexes with acetylcholinesterase compared to butyrylcholinesterase. The kinetic results obtained by HPLC-DAD indicated that berberine noncompetitively inhibited acetylcholinesterase, while butyrylcholinesterase was inhibited in a mixed mode. In turn, palmatine exhibited a mixed inhibition of acetylcholinesterase. The cytotoxic activity of berberine and palmatine standards and plant extracts were investigated against the human melanoma cell line (A375). The highest cytotoxicity was determined for extract obtained from Berberis pruinosa cortex. The cytotoxic properties of the extract were also determined in the in vivo investigations using the Danio rerio larvae xenograft model. The obtained results confirmed a significant effect of the Berberis pruinosa cortex extract on the number of cancer cells in a living organism. Our results showed that extracts obtained from Berberis species, especially the Berberis pruinosa cortex extract, can be recommended for further in vivo experiments in order to confirm the possibility of their application in the treatment of neurodegenerative diseases and human melanoma

    Lifestyle Practices, Satisfaction with Life and the Level of Perceived Stress of Polish and Foreign Medical Students Studying in Poland

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    The adaptation of foreign students to a new country can be complicated due to different cultural values, language barriers and the way university courses are structured. The aim of the study was to analyze the lifestyle practices, satisfaction with life and the level of perceived stress of Polish and foreign students studying various medical disciplines in Poland with regard to chosen sociodemographic characteristics. The study included 231 foreign and 213 Polish students (n = 444) taking different medical disciplines at the medical university in eastern Poland. Three research tools were used: Fantastic Lifestyle Questionnaire (FLQ), Satisfaction with Life Scale (SWLS), Perceived Stress Scale (PSS-10). Additionally, students&rsquo; sociodemographic data was collected. Two-factor analysis of variance (ANOVA) was performed and correlations between variables were also examined. Our research indicated that Polish students obtained higher results in FLQ than foreign students. It also demonstrated a significantly higher level of stress among Polish students in comparison to foreign students. The self-assessment of their health condition, lifestyle, and rank associated to being healthy correlated with FLQ, SWLS and PSS-10. The present research can aid the development of support programs for foreign students so that the cultural adaptation processes would more positively influence their lifestyle and an education environment
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